title: Suppression of the growth of six potentially-pathogenic mycobacteria by beta-lactam/beta-lactamase-inhibitors.
abstract: Drug-resistant tuberculosis and opportunistic infections by mycobacteria in immunocompromised subjects are not readily controlled with the antimycobacterial drugs now available. beta-Lactam antibiotics, the most widely used antibacterial agents, are ineffective against mycobacteria since they synthesize beta-lactamases. The beta-lactam/beta-lactamase-inhibitor combinations are used at present to treat infections caused by other beta-lactamase-positive organisms. Six potentially-pathogenic mycobacteria: Mycobacterium avium, M. chelonei, M. haemophilum, M. microti, M. scrofulaceum and M. simiae, were cultured in 7H9 medium (containing Tween 80 and albumin, dextrose, catalase) at 37 degrees C for 10-14 days, with or without various concentrations (2-100 micrograms/ml) of ampicillin/sulbactam, amoxicillin/clavulanate and piperacillin/tazobactam. More than 50-80% inhibition of the mycobacterial growth was observed at drug levels of 40-100 micrograms/ml in the medium; the drugs were active even when the detergent (Tween 80) was omitted. Against four of the mycobacteria, ampicillin/sulbactam proved to be the most active. The beta-lactam/beta-lactamase-inhibitor combinations may be of use as rational therapeutic agents against mycobacterial infections.
authors.affiliation: GWL Hansen's Disease Center, Louisiana State University, US Public Health Service, Baton Rouge 70894-2059, USA.
authors.forename: K
authors.initials: K
authors.lastname: Prabhakaran
authors.forename: E B
authors.initials: EB
authors.lastname: Harris
authors.forename: B
authors.initials: B
authors.lastname: Randhawa
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003902:Detergents / Q000494:pharmacology; D004338:Drug Combinations; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D009161:Mycobacterium / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D003902:Detergents; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams